Lifting-jack.



F. C. SPENCER.

LIFTING JACK.

. APPLlcmoN men 55121.19. 1913.

Patented Aug. 3, 1915.

FREDERICK C. SPENCER, F GUIFORI), CONNECTICUT.

tirarme-JACK.

Application lecl September'lS, 1913. Serial No. 790,690.

To all whom t may concern.' Y

Be it known that I, FREDERICK C. SPEN- cnn, a citizen of the United States, and resident of Guilford, in the county of New Haven and State of Connecticut, have invented a new and useful Improvement in Lifting-Jacks, of which the following is a 1 specification.

4 is a transverse section in the plane of theA line B-B of Fig. 1. f.

The pedestal of the jack is denoted by 1,k and is made conveniently in the form of a tubular casting with its base portion laterally extended and provided with fillets or webs 2 connecting it with the body p0r-- tion to strengthen it. This pedestal is provided at its upper end with an annular seat 3 for a pawl carrying ring 4? and withv an .annular groove 5 in that portion surrounded "by the pawl' ring 4, for the receptionor` a.

screw 6 to prevent the unintentional disv placement of the ring 4. The said pedestal.

is further provided on its interior with vertical grooves 'Z and 8, see Fig. 4, for the reception of a cross pin 9, in the lower end of the lifting screw i()j to prevent the screw from turning. The flirting screw 10 is intended to extend within the tubular pedestal 1,' freely and is provided at its upper end with a cap 11 swiveled on the end of the screw so that when the cap 11 is pressed against the object to be raised, the screw may turn freely within the cap as is usual. On the body ofthe screw 10, there is lccated a nut 1.2, the perifphery of which. is

orming of the nut provided with teeth 13, wha'. I am pleased 'to call a pinion nut.

The pawl carrying ring 4 hereinabove referred 4to has an extension14, yrecessed at 15, to receive therein a double-acting pawl 16, pivotally secured in position by a pin, 17, extending, in the `present instance,

through the opposite walls of the recess 15.

Speccation of Letters Patent" 7 To holdthe pawl 16 in either `oi? two opposite Vtilted positions, a plunger 18 is .Patented Ang.. 3, i

located in a 'socket 19, in the extension14,

and is pressed toward the pawl by means oi1 a spring 2O seated in the socket 19, back of the plunger 18. The extension 14 is further provided with a pair of depending ears 21, 22, between which the inner end of an operating lever 23 is pivoted by means of a pin-24.' When out of use, the lever 23 may be swung down into the position shown in full lines in Figs. 1 and 2,A and when in use, the leverV 23 is raised into the lines in Fig. l. v l

The'nut 12 rests on the top of the pedestal position shown in dotted 1, and transmits the weight of the screw 10 and whatever is supported on the screw 10, to the top of the pedestal 1. v

In operation, thescrew 10 may irst be adjusted to such a heightas to bring the cap 11 into contact with ,theV part to be raised, by simply lifting the screw 10 and nut 12 upwardly out of engagement with the pawl 16, and then Ahauling the nut 12 up or down on the screw 10, so that when the screw is allowed to drop into the pedes tal and the nut 12`seated on top' of the pedes-s tal, the swivel cap 11 will be at the proper height. The nut is then operated to lift the screw by raising the lever 23 into the position shownin dotted lines Fig. 1', and turning the nut 12 to the right, the pawl 16 heing engaged with the pinion nut as shown nut 12, the pawl rides over one or more of the teeth 13, depending upon how arthe lever is swung backward. The lever is then pulled forward, the pawl engaging the pinion nut-and causing the latter to again turn. These'operations are repeated until the screw has reached the proper height.

When it is desired *to lower the screw, the

pawl 16 is tilted into the position shown in full lines in Fig. 3, and the lever 23 is again f worked back and forth, in this instance talting ciiect on its backward stroke to turn the nut 12 to the leftandthereby lowering the screw and whatever is supported thereon.

ict

1t will be observed that the pedestal may be cast complete without requiring any tool work, that the pawl carrying ring may also be cast complete without requiring any tool work, and that the pinion nut may be cast requiring only the ,screw-threads' te be tooled, and this, together with the threads on the lifting' screw, are the only'parts that require toolinga It will further be observed that the screw,` when the parts are assembled, is locked in position within the pedestal, the pin 9 being inserted in place by allowing the screw i() to project through the bottom of the tubular base or pedestal and then lifted into position to receive the swivel cap 11 which may be secured in position ony the reduced end of the screw 10 by upsetting the end of the screw. An interior shoulder-26 near the' upper end of the pedestal'l, limits the upwardmovement of the screw l0, bythe engagement of the pin 9 with the shoulder.v 4This enables the jack to lhe madein a ver inexpensive manner, and furthermore, t e employment 'of a singlel .pinion nut, and lnient with the pedestal and lifting screw permits the folding ot the j ack when not in f. nee intov a 'very compact form for transport i pedestal, a lifting screw free to move up and tation.- i.

What l claim is:

A `lifting jack comprising 4a 'tubular down within the pedestal, means' for holdi ing the screw against rotation within the pedestal, a pinion nut engaged with the to receive the pin 9,

this in axial alinemasses lifting screw and bearing on top oi the pedestal and free to be lifted bodily with the screw, a pawl carrying ring mounted on. the pedestal below the said pinion nut, a double acting pawl carried by the ring and a ring and pawl operating lever pivoted to 'the ring below the pawl.

2. A lifting' jaclr` ctmprising a tubular pedestal-,l a lifting screw adapted to move up and down within the pedestal, means `for preventing the screw from rotating within the pedestal, a pinion nut engaged with the screwifand. bearing on the pedestal, a pawl this 17th day ciV 

